1. Field of the Invention
The present invention relates to electronic gaming systems and, more specifically, to hand-held positioning controllers or control pads used with a display and an infrared positioning system.
2. Description of Related Art
Most microprocessor-controlled gaming systems use joysticks, control pads, or other pointing systems to allow the user to input data to the microprocessor while playing a game. Two popular gaming systems are the Genesis system, which is manufactured by Sega Enterprises Ltd., and Nintendo Super NES, which is manufactured by Nintendo. Both systems include, as an accessory, a positioning controller which the user holds while playing a game. When the positioning controller is pointed up, a displayed object moves up, and the object similarly moves when the positioning controller is pointed down, left, and right.
One prior art approach to positioning the cursor on the screen in response to the position of the positioning controller is dependent on the television screen size and brightness. The positioning controller of this prior art approach focuses on an area of the television screen and detects when the television raster scan passes through this area. The timing of the detection is then used to determine the position on the screen where the positioning controller is focused. This approach thus uses the television screen as a source for determining position. In so doing, the approach is screen dependent, and position data can vary based on color and intensity of the screen.
This prior art approach additionally has an angular sensitivity that is dependent upon screen size and distance from the screen. For example, the angle between the positioning controller and an area on the screen may be 5 degrees at 5 feet from the television screen and much smaller at 20 feet from the screen. Thus, a user rotating the positioning controller to place a displayed curser in an upper portion of the screen must rotate the positioning controller more when sitting near the television and less when sitting further away from the television. This angular sensitivity can render positioning of the sensor difficult when the user is positioned far away from the screen. Moreover, a user must adapt to different sensitivities every time the positioning controller is used at a different distance from the television.
Further, cursor position jitter can be high with this prior art approach, and the accompanying averaging algorithm used to stabilize the varying data is often less than optimal. This averaging causes significant artifacts to be visible when the cursor is moved. Thus, a need exists in the prior art for a positioning apparatus that is both convenient and accurate.
The present invention resolves the above-mentioned shortcomings with a positioning apparatus which uses infrared light for generating positioning data. An infrared beacon is placed near the television, and a positioning controller having an infrared sensor derives positioning data from reception of infrared light from the beacon. The present invention measures the angle of the controller relative to the beacon.
The positioning controller of the presently preferred embodiment is held by a user during operation of games run by a microprocessor. By changing the pitch of the positioning controller, a user can move a displayed object up and down. Also, by changing the yaw of the positioning controller, the user can cause the cursor to move left and right on the screen. The movement of the cursor on the screen roughly corresponds to the angular movement of the positioning controller held by the user.
If the present invention is set for a full scale at 20 degrees, the full scale will be the same whether the positioning controller is 1 foot or 100 feet away from the beacon. The angle for full scale can thus be set so that rotation of the positioning controller to the set angle results in the cursor being positioned at an edge of the television screen. According to the present invention, a user can rotate the positioning controller the same amount for the same displayed cursor movement, regardless of the distance between the user and the television. The present invention operates independently of screen color, brightness, and size.
A preferred embodiment of the present invention includes a positioning controller having a receiving side for receiving light from a light source. The receiving side includes an axis extending perpendicularly therefrom, and a vertical plane and a horizontal plane intersecting at the axis. The positioning controller includes three sensors. The reference sensor is positioned between the other two sensors, and is masked to receive light from a predetermined range of acute angles measured from the axis. One of the other two sensors is a vertical angle sensor that is masked to receive a larger quantity of light from a first side of the horizontal plane and from a second side of the horizontal plane. The third sensor is a horizontal angle sensor that is masked to receive a larger quantity of light from a first side of the vertical plane than from a second side of the vertical plane. The positioning controller further includes circuitry for determining an orientation of the positioning controller using the amounts of light received by the reference sensor, the vertical angle sensor, and the horizontal angle sensor.
According to the presently preferred embodiment, the lower half of the vertical angle sensor is masked so that reception of light into the vertical angle sensor is limited when the vertical angle sensor is pointed above the light source, and the reception of light into the vertical angle sensor is promoted when the vertical angle sensor is pointed below the light source. Similarly, the right half of the horizontal angle sensor is masked so that reception of light into the horizontal angle sensor is limited when the horizontal angle sensor is pointed to the left of the light source, and the reception of light into the horizontal angle sensor is promoted when the horizontal angle sensor is pointed to the right of the light source. By looking at the differential amounts of light received by the horizontal angle sensor and the vertical angle sensor, and comparing these amounts to the amount of light received by the reference sensor, orientation data describing the pitch and the yaw of the pointing device can be determined.